What I'm trying to say is,I don't think it's a bug. When you take the quest game randomly spawns one of these thats under the contracts list and one of the npcs thats under the targets list. Think of it as lottery.
You have 1/12 chances that you'll get same contract as before,and 1/11 chances that you'll get same target as before,which roughly makes it 0.5/12 chances that the contract giver and the target are going to be the same. Unless its scripted so each contract giver always gives the same target,then it would be 1/12 chances that you'll get completely same quest.